A new species of Gundlachia, Gundlachia dutrae
described from northwest Brazil.
It is distinguishable from other congeneric species by
characteristics of the shell, radula and internal organs.
Shell relatively high. Aperture near-circular; periostracum dark
brown without periostracal hairs. Apex slightly inclined to the
right, projected but not hooked, with an apical depression
surrounded by a sculpture of well-marked irregular punctations.
Shell surface with prominent radial sculpture. No septate specimens
were observed. Ratios (n=59): shell width/shell length = 0,66-0,79
(mean 0,73); shell height/shell length = 0,32-0,45 (mean 0,37);
shell height/shell width = 0,43-0,63 (mean 0,51).
Body of normal ancylid type; mantle pigmentation dark brown or
black, concentrated along the mantle collar.
The dorsal surface of the right anterior muscle is elongated and
medially constricted. The left anterior and the posterior muscles
are almost elliptical. Adhesive area is V-shaped.
Pseudobranch unpigmented bearing a very small and thin dorsal
Ovotestis with more than 25 unbranched diverticula. Ovispermiduct
with seminal vesicle rather developed. Elongated nidamental gland
continuous with the glandular wall of the uterus. Nidamental gland
appendix ending into a bulbous swelling. Spermathecal body almost
rounded. Well-developed prostate with five long diverticula.
Ejaculatory complex with long glandular flagellum, without a penis
or true ultra-penis. "Penis sheath" developed. "Ultra-penis"
projected as a tube inside the lumem of prepuce, with a slit between
"ultra-penis" and "penis sheath".
Rachidian tooth tetracuspid, with two median cusps assymmetrical and
aculeated. Lateral teeth tricuspid, with a reduced endocon and a
prominent mesocon. A well marked gap occurs between meso and
ectocon. Marginal teeth similar to lateral ones.
Jaw T-shaped, with about 28 dorsal plates.